Description from Flora of China
Bupleurum falcatum var. stenophyllum H. Wolff in Handel-Mazzetti, Symb. Sin. 7: 713. 1933; B. falcatum f. stenophyllum (H. Wolff) P. K. Mukherjee & B. D. Naithani; B. marginatum f. stenophyllum (H. Wolff) H. J. Chowdhery & Wadhwa.
Plants 25–60 cm. Leaves narrow, 3–10 × 0.3–0.6 cm, cartilaginous margin narrow. Bracteoles longer than the pedicels. Fl. Aug–Sep, fr. Sep–Oct. n = 7*.
The taxonomic status of var. stenophyllum requires further study. Some authors treat it as conspecific with Bupleurum marginatum without any infraspecific designation, but the difference in chromosome numbers favors treating it as a separate taxon, perhaps as a separate species.
Alpine forests, river banks, roadsides; 2300–4000 m. Qinghai, Sichuan, Xizang, Yunnan [?Bhutan, ?E Nepal].